1. Field of the Invention
Aspects of the present invention relate to a mobile system, a method of managing a path in a multi-hop cellular network, and a data frame used in the mobile system.
2. Description of the Related Art
In a multi-hop cellular network, data can be transmitted via at least one relay station when data is transmitted from a base station to a terminal. A multi-hop system can expand a service area using relays that are inexpensive to establish and maintain, and also can decrease a number of base stations that are expensive to establish and maintain.
In a single-hop system, a predetermined terminal must pass a base station and a network entry process to connect to a network. The terminal scans for base stations adjacent to the terminal. When there are a plurality of base stations, the terminal registers itself in a base station having the strongest signal strength from the base stations. Similar to a multi-hop cellular network, a terminal scans for a base station or a relay station existing adjacent to the terminal, and connects to a base station or a relay station having the strongest signal strength. If a terminal is connected to a relay station, the terminal can be connected to a base station that serves the relay station via the relay station. Generally, in an existing system, once a terminal establishes a path to a base station, the terminal transmits/receives data with the base station via the path until a specific change occurs, such as a transfer of the terminal to a different location. To receive data, a terminal requests bandwidth from a base station via the path, and is allocated resources via the path.
Except when a terminal is first powered on and performs a network entry process, a terminal having received a service from one cell moves to another cell via a handover process. In the latter case, in the existing method, it is usual to select a base station or a relay station having the highest signal quality associated with a signal strength of an access link from among target base stations or relay stations.